


The Game

by MissKierie



Category: Undertale (Video Game)
Genre: Anal, Caliginous Romance | Kismesis, Dirty Talk, Double Penetration, Gender-Neutral Pronouns, Hate Sex, Impact Play, Light Angst, Masochism, Masturbation, Oral Sex, Other, Quadrant Vacillation, Reader Is Not Frisk, Reader-Insert, Rough Sex, Sadism, Teasing, Vaginal Sex, ectodick
Language: English
Status: In-Progress
Published: 2015-12-26
Updated: 2016-01-11
Packaged: 2018-05-09 14:24:35
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 9
Words: 13,750
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5543201
Author URL: https://archiveofourown.org/users/MissKierie/pseuds/MissKierie
Summary: <blockquote class="userstuff">
              <p>You think you made your intentions quite clear. Aiming your pelvis at him during conversations. Intermittently laughing too hard and rolling your eyes at his jokes. So. Why hadn’t anything happened yet?</p><p>Apparently, he knew. He knew all along. Teeth pull back, he’s smirking like a motherfucker, “it’s kinda fun to watch you squirm.”</p><p> Alright. So he wants to be like that, does he? Two can play this game.</p><p>Black romance with Sans. Smut in almost every chapter.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> *pounding fists on table* More black romance with Sans!! I just can't imagine being red with that guy. So, I wrote this. I have no idea how long this is going to be. I have no idea what's gonna happen. Making it up as I go along. The reader's gender and genitalia are left to interpretation.

A brush of elbows. A hand on your lower back. Eye contact that lasts just a little too long. A flicker of cyan. It was constant. It was starting to get annoying.

You think you made your intentions quite clear. Aiming your pelvis at him during conversations. Intermittently laughing too hard and rolling your eyes at his jokes. Bragging about your limited knowledge of quantum mechanics. Accidentally leaving your door slightly ajar while masturbating. Maybe saying a certain someones name a little too loud at climax. That’s how people flirt, right?

So. Why hadn’t anything happened yet? Why hadn’t he responded AT ALL? Not even to tell you to chill. Or to close your door. He remained Sans. Smiley, winky, hands-in-his-pockets Sans. Alright, enough subtly. Tonight you’ll just spill your guts up front. Hey, skeleman. I’m into you. Wanna touch butts?

On the couch. Touching knees. Legs spread, casually aiming your torso at Sans as you both watch a movie. Papyrus was on the other side of you. Completely aware of the situation at hand, he excused himself to his room. He’s been rooting for you for months. You’re nervous. Breathing picking up a bit. Heart rate increasing. Sans gives you a side glance, grin as static as ever. You open your mouth to say something, but he’s already talking.

“something on your mind?” 

You freeze for a minute. Mind, blank. Fuck uh… what were you about to say. You close your eyes and take a deeeeep breath. “Sans,” you manage to spit out. “I’m uh. I’m pretty into you.” Suddenly your knees touching is way too intimate. You turn to face the TV, pulling your leg away, looking at him out the corner of your eye. “Would you ever wanna-“

You’re interrupted. “yeah i know,” he says it like it’s the most obvious thing in the world. “i’ve known for a while. you aren’t really good at subtlety, kid.”

What. The fuck. Your whole face is burning at this point. You’re embarrassed… and excited. “Then,” you fiddle with the seam of your pants, “why haven’t you said anything?”

Teeth pull back, he’s smirking like a motherfucker, “it’s kinda fun to watch you squirm. you try so hard.” Skelearms stretch back and cradle his head as he leers at you. He moves his leg, his whole calf now pressing against yours. “it’s pretty cute.”

He was just messing with you the whole time? You’re pissed. This is bullshit. “You fuckinggg. Fucking fuck fucker.” You forcefully push against his leg with yours and scoot all the way over to him, angrily squishing your whole body against his so he’s sinking into the corner of the couch. “I’m gonna fucking. Throw you out the goddamn window.” 

He laughs loudly and doesn’t even bother to fight you. “hey now. a guy could get the wrong idea and mistake this as something… caliginous.” He looks at you with lidded eyes and blushing cheeks, like he’s just said the sexiest thing in the world.

Oh my god. That fucker. “Don’t you bring Homestuck into this!! This is straight up rage! The fact that I also wanna fuck you is completely unrelated to what’s happening right now!” You decide to take control of the situation by being completely honest. You’ve laid your cards on the table. Your move, Sans.

His grin widens, the flecks of light in his sockets brighten and then. Darkness for a fraction of a second. You’re on your back. On the couch. Sans is looming over you, legs spread around your hips. He’s got a hand pressed directly on your sternum. Applying light pressure. “i bet i can make you _squirm even more_ …” 

You moan shamelessly as he rubs small circles between your breasts, continually pushing down. “Fuck yeahhh,” you huff, it’s about time he started touching you. Raising your leg, you grind your knee into his crotch, uncomfortably bumping his pubis and ischium. “Squirm? HAHA.” Drag your toes across his femur, pushing up his gym shorts. “What makes you think you could even turn me on? Let alone get me off-aah!”

Solid phalanges unexpectedly seize your left breast. You squeak and make an expression that just screams yearning. He chuckles at your immediate reaction and gives you another squeeze. “you wanna play that kind of game? alright. no _skin off my nose._ ” And with that he’s immediately leaning away, standing up, and walking to the kitchen. You stutter things like ‘what’ ‘where are you going’ and ‘did i do something’ as he opens the fridge, grabbing a bag of chips. He just smiles, waves a knowing finger at you and goes upstairs to his room.

“Whaaaat.” You pout. Cross your arms and sink down into the couch. Fucking jerk ass skeleton asshole motherfucker teasing you and then fucking. Acting like nothing happened. You sigh heavily. After a few minutes of sulking and waiting to see if he’ll come back, you peel yourself from the couch and go to your room. Quickly remove the most hindering pieces of clothing and sprawl out on the bed, both hands between your legs. Roughly toy with yourself, not wasting any time. You’ve got to get rid of this irritation and sexual frustration. Clasp your breast the way he did. Spit in your hands. Scream his name disdainfully. Force an orgasm out of your body. It’s moderately satisfying. It’ll do. Wipe your hands off on your shirt. Come up a cunning plan. You know Sans likes socks. He likes the color of your flesh, too. Tomorrow. Thigh-high socks. Booty shorts. Crop top. Two can play this game, you fucking magical monster man. Let’s make this relationship as black as possible.


	2. Chapter 2

**Notes for the Chapter:**

> Two chapters in one day haha well. They're short. They'll probably all be like this. Writing this shit is awesome. It's so fun. Thank you guys for reading it. Readers gender and genitalia are left to interpretation.

Next day. Makeup perfect. Eyebrows, on point. Hair, one day dirty. Has a nicer shine that way. Revealing outfit put together. The socks and top cover your limbs, but your ass and upper torso are pretty exposed. Look in the mirror, lovingly pat your belly, beaming with confidence. It’s a cheap tactic to get back at Sans. But you’re a simple human. And you know it will work. It’ll at least shake him up enough to even out the playing field. A little. Maybe.

Whole day to spend at home. Plenty of opportunities to ‘accidentally’ turn that skeleton on. He’ll be in and out as he switches between jobs. Maybe bake a pie. He likes those too. Vacuuming the downstairs carpet when you hear his door creak open. Catch yourself when you try to greet him. Wait for it. Pink slippers shuffle down the stairs. His eyes are still clouded with sleep. Rubs one and yawns, ugh, he’s so cute. You smile coyly at him, consciously arching your back and wiggling your butt as you push the machine across the floor. The lights in his sockets brighten and dilate as he sees you, just for a second, but you notice it. Turn off the vacuum as he moves toward the kitchen. Call out to him, “good morning, sleepybones!” He grunts in response. Grabs some food and then he’s out the door. Muwhahaha. Eat that, Sans. Suck a diiiick. Have a nice day at work.

Baking a tomato pie. Papyrus is fascinated by the idea of eating a vegetable pie. You tell him tomatoes are scientifically fruit because of the way the tomato develops in the ovary of the flower, and how the seeds remain inside it. The concept makes him frustrated. He throws his arms up when you tell him bean pods are technically fruit and strawberries aren’t. He starts to go on about the idiosyncrasies of human science. You giggle, kiss him on the cheek to help him calm down, and ask if he can spread the pie shell into the dish while you slice the onions. He rips a hole in it and has to start over. He says he’s appreciative of your baking lessons.

The house smells like fresh pie crust. In the kitchen washing the dishes you dirtied. Papyrus happily watching MTT. Sounds like a reality show. Hear the front door open, your heart jumps. Sans is back from his first shift. Cold air blusters through the house. “WELCOME BACK, BROTHER!” They proceed to chitchat about their days. You smile to yourself. Nothing is more heartwarming than the love those two have for each other.

Abruptly, someone’s behind you. They’re cold. It’s Sans. Hips thrust into your butt, forcing your body against the kitchen counter. Your hands shake as you hold the knife you were just washing. Ribs press against your back, his breath on your neck, “keep it down…” He smells like crisp snow. Use the blade of the knife as a mirror to see him perched on your shoulder. “you little shit. do you even know what you’re getting yourself into?” Hands are reaching around you, up your shirt and clasping around your breasts.

“FUCK,” you yelp, “that’s COOOLD!” 

Papyrus responds quickly to your scream, “HUMAN??? ARE YOU AL-“ Turn to see Pap peeking his head in the entry way. Neither you nor Sans move. You raise the hand not holding the knife and wave gayly to him. He realizes what’s happening immediately, rolls his eyes, and returns to the living room.

Sans growls quietly and grabs a fistful of hair, jerking your head to look forward. Oh my god you’re ecstatic, you didn’t think he’d react SO strongly to something so small! Maybe a few more sexy outfits and slow femur strokes, then you’d get a reaction. But this, wow. You experimentally grind your ass back against him and he chokes on his own spit. Okay, that’s amazing, he’s coming apart so easily. You let out a bellowing laugh before he thrusts you into the counter again, his pubic bone bruising your cheeks, your front pushed uncomfortably against the cabinets. “ _Heehee._ Somethin’ on your mind, Sans?” The words drip from your lips like venom.

He doesn’t say anything. One skelehand grasps your wrist, gripping so tight you drop the knife into the sink with a loud clatter. The other reaches down your front, harshly rubbing the heat between your legs. God, it feels good to have him finally touch you there. You moan loudly with purpose; apparently Sans doesn’t like Papyrus knowing what kind of mischief he gets into. Let’s dig into that wound, shall we? The hand moves from your wrist and slaps over your mouth. Your snicker into it, running your tongue between his metacarpus’. He snorts and massages your center haphazardly, “you’re in trouble now, kid.” You feel teeth nipping at your ear. He cups his hand around your entire crotch, “you know, i could make a meat pun right now… but i’d probably _butcher_ it.”

And with that he’s gone. You turn, but no one’s there. Commercial playing on the TV in the other room. That. Motherfucker. You let out a small scream as you start to finish off the last of the dishes. Back to your room. Back to masturbating. With a hefty toy this time. You deserve it after doing that to Pap.


	3. Chapter 3

**Notes for the Chapter:**

> ( ͡° ͜ʖ ͡°) Sans is an asshole. Enjoy! The readers gender is left to interpretation and they have a vagina.

You didn’t see him for the rest of the day. You know Sans must’ve come home at some point. Half of the tomato pie is missing. But it was eaten straight from the dish with a fork. Rude. Probably teleported to avoid you, the fucking coward. 

Welp. It’s the next day. Back to work. At least it means you won’t be tortured with sexual teasing by that fucking blue coat ass wearing skeleton. Some peace and quiet at your job at the local shop. It’s an easy position. You take inventory, open, manage the counter, then close. And you know. All the other shit you do when you work at an RPG shop. It’s only difficult because sometimes you’re stuck there for 9 hours straight. It’s been 12 hours a few times. Whatever. It pays the rent. And the customers are excited to interact with a human. 

Slow day today. Haven’t seen anyone in over two hours. You hoped it would be busier. Mind keeps wandering to Sans. Hey, remember yesterday when he slammed his hips into you? When you could feel every bone of his rib cage against your spine? Fucking stop it, brain. The sexual energy travels right to your groin. You ignore it. Can take care of it later when you’re home.

Leaning forward on the counter as you tap your foot on the rung of the stool. It’s quiet. Then out of fucking nowhere, there’s a shock of static in your ear and hands on your knees. WHATHEFUCKyou screech and kick back from whatever was touching you, falling off the stool. Everything goes black for a second. Body, immobile. Blue glow around you. You’re. Floating?

Oh my god. SANS.

He’s sitting cross-legged under the counter, left eye blazing with cyan magic, hand outstretched, shoe print on his face. He cackles, making the ‘come here’ motion with his fingers and you’re hovering back to the stool. Placed on it, in almost the exact position you were in before. His face is right between your open legs. “sorry, kiddo. didn’t mean to spook you like that.” Glowing eye flashes back to the normal white pinpricks and you have control again. 

Hands clenched, teeth gritting, heart pounding. You take a deep breath, not even bothering to look down at him, resting your palms flat on the counter. “I think I might actually kill you. Like, that’s a legitimate possibility.” Skelehands run across your calves, pinching the dense muscle, then sliding up the outsides of your thighs. You continue to inhale slowly. Fuming and still rushing with adrenaline. 

Glance down at him as he comes closer. Skull teases between your legs until he’s a fucking inch away from your junk, resting his chin on the edge of the seat. What the hell does he think he’s doing? He takes a full, pronounced intake of air and you blush so hard your ears burn. “hey, pal. that’s some pretty heavy talk.” Rubs his face against your inner thigh, wiping off the marks your shoe left. “are we gonna need to get an auspistice?” He looks up at you, a glint in his eye.

You just. Ugh. Lean forward on the counter, hiding your face in your hands. “I’m at work. You can’t do shit like this here.” Nasal bone presses into your crotch and you groan with embarrassment as he takes another deeeeep breath. His hands move up to pull open the button of your pants. “Sans. I’m serious.” The words are genuine, but you still stand up to help him pull the pants down to your ankles. Sit back down. Skull right back against you, mouth opening slightly, bottom teeth scraping across your panties. Holy fuck. This isn’t okay. You should be stopping him.

“don’t worry, i’ll be quick. you’d probably like getting caught anyway, you dirty freak.” Well. He’s not wrong there. This is super exciting. Anyone could walk in at any moment. Even your bunny boss. You can feel his teeth vibrate against you as he talks. 

“This is so fucked up…” your voice trembles. He snickers into you, incisors pinching at the meaty flesh of your thigh. Try to keep your noises to a minimum. Don’t want him to feel anymore satisfaction than he already does. A thought comes, “do you even know what you’re looking at down there?”

One hand travels up the rolls of your stomach. The other pulls your panties to the side, revealing your blood-engorged privates. Even you can smell how aroused you are. Fuck. “you really think i’d get myself in this situation without doing some research first?” His thumb trails from bottom to top of your wet core, swirling lightly around that swollen bundle of nerves. Gets a small whimper out of you. “humans have simple anatomy anyway,” his voice hasn’t changed it’s tone at all and that pisses you off.

Static shock is ringing in your ears again. His left eye is blazing with cyan magic, casting light on your reddened flesh. Something warm and slick pushes between your folds and you can’t help but let out a surprised moan. “Holy shit, what the fuck is that.” Sans’ head tilts back, lewdly running the blue, translucent appendage up you, adding a flick at the end. It’s just. Appearing from his teeth? It doesn’t even have a base.

“you don’t know a lot about monster magic, huh?” He talks normally?? What the fuck. Shouldn’t he be lisping or something? Your legs are shaking. You tense them. Fingers nervously scratching at the countertop. Someone could walk through that door right now. “tangy,” he mumbles, another long lick up your crease. It feels really fucking good. Soft and smooth. “fun first date, right? i love eating out.”

“Ugh, shut the fuck up, Sans.”

The twitching tip finds your entrance. You let out a muffled moan as he enters you, stretching you out. Nowhere near as much as your toys do, but FUCK, this is hot. His thumb finds the nerve bundle at your crest and circles quickly. Hnng, holy shit. Other hand resting on your love-handle, groping at it occasionally. He preemptively giggles, making the ‘tongue’ vibrate inside you, “heh, cunnilingus. big word, what a mouthful.” Starts thrusting in and out of you. 

Groan in exasperation at his joke, reaching down and jerking his head so he’s completely pressed against you. He just laughs and fucks you faster. Oh god oh god anyone could open that door at any second. Sans' head is between your legs, he's fucking you with his magic tongue thing. Goddamn, is this really happening? He continues for a few minutes, humming happily into your crotch. Climax approaching. Dripping on his chin. “Fffuck, I’m close…” On the edge of your seat, getting as close to his mouth as possible.

Still thrusting wildly inside you. His glowing iris stares at you intensely. “i told you you were in trouble.” You aren’t listening. So close, so close, just a little more. “here’s your punishment.” In a flash of darkness and electricity, the tongue has vanished. Sans is gone. 

Before you can even react, the wooden door to the shop is flying open. You panic and crouch under the counter, hands fumbling as you pull your pants up. Stand, undone pants around your waist as Doggo stops in his tracks. Raises a furry eyebrow. He must be able to smell what just happened. “H-HI!” you choke out, immediately buttoning your pants and pulling your shirt down. You smile stupidly, face as flushed as it could be. “WHAT CAN I,” you pause, clearing your throat, “how can I help you?”

You sell Doggo a couple of snacks with a few awkward exchanges and he’s out the door. The moment he’s gone you literally collapse on the door and cradle your knees to your chest. He’s dead. That skeleton is fucking dead. 

Still so wet and sexually ravenous. Four more hours pass with no customers and you’re done for the day. Go home. Papyrus has dinner ready. Of course, Sans is nowhere to be found. Go up to his room just to kick the door a few times. Masturbate like crazy in your room, biting a pillow to mute your livid moans. Next day off, you’ll visit him at work. Make those bones quake. He’s going down.

**Notes for the Chapter:**

> Oh my god this fucking chapter. I hate that skeleton. I love him. Sigh, I tried REALLY hard to make a story with 100% ambiguous genitalia but. Trying to write oral sex for that is really hard >_> so I went with a vulva cause I have one of those. Sorry. I hope it doesn't disappoint anyone.


	4. Chapter 4

**Notes for the Chapter:**

>  **NOTE: THIS CHAPTER CONTAINS VOMIT.** I wouldn't call it emetophilia, but there is puke. The reader getting their revenge. This one took a while to write. Idk if I like it. but. here it is! Readers gender and genitalia are left to interpretation. Enjoy!

This fucking guy… Anytime you interact with Sans, he just gives you a knowing grin and acts like nothing happened. He did compliment your pie. He even had the gaul to ask you to bake another. You two still watch TV together, eat meals together, go to Grillby’s together. But there’s an obvious layer of tension emanating. It’s so bad, even Papyrus mentioned it. He’s worried. You tell him it’s fine. You lie, saying you love Sans. The reality couldn’t be farther from the truth.

The genuine fury of what he did to you hasn’t subsided in the slightest. It’s probably gotten worse. You won’t be satisfied until you get your revenge. It’s your day off. Sans is working at the Hotland hotdog stand today. You packed him a lunch, knowing he’d forget it. Tomato pie piece included. HAHA welp, looks like I need to deliver this!

Skimpy outfit again. You’re going to Hotland, after all. Sprint to the riverbank. Smile at the River Person, but don’t pay much attention to their words. Too busy running your plan over and over through your head. It might not work. What’s plan B if it doesn’t? It'll work. Maybe.

Take your time walking to his stand. Don’t want to get anymore sweaty than you already are. See him in the distance. Leaning back in his chair, feet propped up on the counter. Pool of melted snow around the base. He doesn’t notice you until you plop the MTT lunchbox next to his feet. He opens one socket at you as you sit on the corner of the counter, facing him. “hey buddy. what’s this?”

Lean back on the post, “your lunch!” He gives you a warm smile, taking his fingers out of his pockets, two ketchup packets falling out, and resting them his ‘stomach’. “I’m also here for vengeance,” you say sweetly. Grab a hotdog and quickly scarf it down. It tastes okay.

He looks at you suspiciously. “vengeance, huh? that’s fair.” He shrugs, “you know, that wasn’t the first time i’ve done that. you know your boss-“

You cut him off with an irritated protest. The last thing you wanna hear about is his past sexual partners. Push at his legs until he’s forced to tuck them under the counter. Glance around quickly to make sure no one’s around, then crouch and shimmy under the stand between his legs. He just chuckles at you and doesn’t contest in the slightest. Get in a comfortable position, making sure no part of your body is peeping out the sides. Ugh, it smells like ketchup under here. Ketchup and old sweat. Sans needs to wash his jacket.

Reach up and trace the lining of his pelvis through his shorts. Slip your fingers under the waistband, finding where his spine meets his hips. He lets out a serene sigh, “that feels nice, kid.” Heh heh. That’s right. Get nice and comfortable, you fucking prick. Fingernails finding the spaces between segments of vertebrae. Pushing in too far gives you a small shock, making your hair stand on end. Must be magic holding him together.

“Think you could show me… a little more of your magic?” look up at him, making a jack off motion with your hand. If he can make a tonguetacle appear from his teeth, he can probably make some genitals.

A bead of sweat forming on his forehead. Fixed grin looking more anxious than you’ve ever seen it. That makes your body stir. All unassertive and shy, you feel so much power over him right now. He clears his throat and the white dots replace with one large blue iris. A glowing bulge gradually develops in the crotch of his shorts. You beam and immediately touch it, running your palm across the smooth protuberance. Breath hitches in his throat. He can feel that? Hell yea.

Fingers curl under his waistband. He moves his hand to yours. He’s shaking. “it’s uh. a work in progress.” What the fuck does that mean? Pull down the front of his shorts, a semiopaque cock bouncing out in your face. It’s a pretty good size. Nice and thick. But… it’s a human dick. Thick veins. It looks like a cock you’d see in porn. Even circumcised, scar and all. Can guess how he ‘studied’ his human anatomy. You push your lips together and snort, letting his shorts rest at the base as you seize it with your dominant hand. He gasps and quickly shoves both hands in his pockets. His cheeks are blushing blue. Looks like he’s waiting for you to say something, “what’s wrong, cock got your tongue?”

“It’s _okay,_ ” you comment casually as you give the shaft a few meager pumps. “Kinda boring,” lean forward, rolling the flat surface of your tongue across the head. Doesn’t taste like anything. Makes your tongue tingle, tho. He lets out a nervous cough and turns it into a laugh. “We can build a better one later.” Put your mouth over the tip, one hand gripping the base, the other traveling across the various bones of his spine. Maintain eye contact.

He huffs and slouches in his chair, “like with spikes? or a giant horse dick or something?” Give him a ‘i’m so sick of your bullshit’ look as you roll your tongue across one of the veins. “hey,” he winks at you, “i don’t know what kind of kinky stuff you’re into. throw me a…” He pauses as you take half of his entire length inside, pulling back and coating it with spit, “ah, a bone here.”

Footsteps in the distance. He picks up his chair and scoots in as much as possible, giving you the opportunity to shallowly bounce your head on his cock, earning you a strained exhale out of him. Based on the pitter-patter strolling, it’s probably Vulkin. Pull your head back to lather up your fingers, then shove them the front of your shorts. You aren’t that wet, but seeing Sans squirm like this is fucking arousing. Diddle with your swelling nerve bundle as you jack off his base with your other hand, returning your lips to the tip.

Sans glances down at you briefly, then talks to the innocent monster wanting a snack. “hey buddy, what’s up? wanna buy a hotdog?” His voice sounds surprisingly normal. The Vulkin makes a cute sound, and you just know his little eyes are making hearts right now. Jingle of a few coins hitting the counter above you. “thanks.” He leans up and shuffles with the things on the counter, can hear the familiar fart of ketchup being squeezed onto the meat. Still sucking happily on his magic wang, Vulkin none the wiser. “here’s your ’dog.” He stands up a little to reach over and plop the hotdog into the Vulkin’s waiting… volcano. 

A few pitter-patter steps and Sans is letting out a heavy sigh, leaning back into his lounging position. “yeah, okay,” reaches up and wipes off some sweat that accumulated on his skull, “i can see how this would be stressful.” You chuckle with him still in your mouth, reaching up to grab his sleeve and resting his hand on your head. Still rubbing your center with your other hand. Spreading legs in just the right way. Might even cum at his rate. You moan into him as he fists the hair on the back of your head, forcing himself deeper inside. That’s it. Keep going skeleman. Your due punishment will soon be upon you.

Continue like that for a few minutes. Give no warning when you bring yourself to orgasm, eyes rolling back in your head as he thrusts frantically into your mouth. No time to bask in the aftershocks, there’s retribution to be had. Haven’t taken the last inch or two of his length, despite his efforts. Pull back, a lewd string of saliva connecting the two of you, and say “fuck my throat, cum in my mouth.” Skelehands slap on both sides of your face and your forced onto his cock, penetrating your throat. You gag and try to pull away, but he keeps you there.

He's really getting into it. “ah yeah, take it all, you fucking filthy human,” he grunts as he thrusts into you as deep as he can. The obstruction in the back of your throat causes your body to react, vomit erupting from your lips, half chewed bits of hotdog and stomach acid coating his dick. He howls and jerks away from you, but you grasp his dick with your hand and let the vomit drip into his shorts. You guffaw and wad up a spitball of saliva and puke in your mouth, hurling it at his face while he’s trying to get away from you. Blue eye blazing in an outrage, he stands up, chair he was sitting on toppling down the cliff behind him.

Footsteps and the clatter of armor. You burst out laughing as you scramble from your hiding spot, immediately darting back towards Snowdin. Pay no attention to the royal guards you pass who are probably going to Sans for their afternoon refreshments. You look back to see Sans, eyes back to normal, brushing off as much of the mess as he can. HAHAAA have fun at the rest of your shift, fucker!!!

Wash your mouth out with river water. Ride back home, take a bath, lotion up your entire body. You deserve a treat after successfully getting your revenge. You wonder what he’ll do to you in retaliation. Whatever. You can worry about it later.

**Notes for the Chapter:**

> http://undertailsht.tumblr.com/post/137191683348/sans-glances-down-at-you-briefly-then-talks-to?
> 
> Someone drew fanart!


	5. Chapter 5

**Notes for the Chapter:**

> Buttstuff? We'll see. Thank you for reading and enjoy! The readers gender and genitalia are left to interpretation.

A knock on your door. You quickly grab your bathrobe and cover your naked form. Papyrus comes in, face glowing, eyes as bright as you’ve ever seen them. “HUMAN!!!” he takes your hands into his and leans down to kiss them, “I DON’T KNOW WHAT YOU DID, BUT SANS DID HIS LAUNDRY! FOR THE FIRST TIME IN ALMOST A YEAR!” You make a genuinely happy smile and nod as he continues. He asks if you confessed your love to him. Laugh lightly and say no, not yet. Asks you to continue whatever you’re doing. Thanks you and says he hasn’t seen his brother this active in a long time. Haha. Well. Maybe you’re not that bad of a kismesis after all.

In bed, reading a book. Not paying much attention to it. Sigh and realize you’ve read this entire chapter without absorbing any of it. Page back to start over. Your door flies open, Sans storming in and slamming the door closed behind him. You jump and grin stupidly, surprised to see him so soon. His outfit is different, ripped jeans, black long sleeve sweater, and a pair of Pap’s socks. Points a finger at you, “you think that shit was fucking funny?!” Lawl, he’s so mad. His left eye starts blazing as he stomps over to the bed, you notice the bulge growing in his pants.

You raise your eyebrows and close your book. “Well, you seemed to enjoy the first part of it.” Self-satisfied. Smug.

He fucking _growls_ and crawls onto the bed, grabbing the book from your hands and chucking it at the wall. “i haven’t even gotten off yet,” he grumbles as he grabs your ankles, yanking your entire body down so you lie on your back. He smells like laundry detergent. 

You struggle to pull the robe around your exposed body, starting to blush as you laugh. “What makes you think I’ll help you with that?”

Sans grabs a handful of your flesh, literally picks you up, and throws you on your stomach, knocking the wind out of you. Robe flying open, naked front touching the comforter beneath you. His voice is laden with ardor, he says, “you won’t be doing anything.” Holy shiiit. Latch onto the headboard of your bed, pulling yourself up so you can rest your head on a pillow. He’s pushing the robe up to your waist, revealing your bare ass. Runs his skelehands up the back of your thighs and around the curvature of your cheeks. “fuck,” he mutters, “humans are so soft.” You moan and thrust back into his hands, only to be met with an open-palmed slap, “hey,” he says firmly, “i’m not here to make you feel good.” Another slap to the same reddening handprint, sending a few tremors down your spine.

You feel him get on top of you, warm crotch pressed against your crack. Your gasp of pleasure is cut off as his weight crushes you into the mattress. God, he’s heavy. All of the air is forced out of your lungs as he puts his entire weight on you. You can hear the hiss of a zipper and the rustling of denim. His hands rest on both sides of your head, something warm and smooth pressing against your ass. Shifts his weight to your hips, slipping his member between your cheeks. 

“Ooh!” you wheeze, finally able to breathe. Moves his pelvis, shaft grinding across your orifice. Oh god, is he going to fuck your ass? Reach towards your end table. “W-wait,” you stammer, opening the top drawer, where all your toys and accessories are kept. Phalanges wrap around your upper arm, throwing your hand back to the headboard. Thrusts roughly against you, the dry friction uncomfortable. “Ahh, you need lube.”

Suddenly, the same phalanges are being shoved in your mouth. You accept them and suck, tongue coating them with saliva. “no i don’t.” Takes his hand back and arbitrarily runs it down your crack, quickly replacing them with his member. “you don’t deserve it.” 

You’re about to panic and insist, you fucking NEED lube if you’re doing buttstuff. Before you get the words out, hands slap onto your cheeks, pressing them together around him, “i’m gonna hot dog **you** this time.” Bucks into you, feeling every inch of him as he slides past your sensitive muscle. The spit provides some lubrication, but it won’t last long.

And it doesn’t. After maybe a minute or two of thrusting, you’re bone dry again. Each thrust of his cock burns. You’re kind of disappointed in yourself for enjoying it. Can feel how wet and swollen your crotch is. That dick could be put to much better use. “Fuck me,” you whimper, watching him over your shoulder. Flames spilling out the closed crack of his eye, cheek bones blue, starting to drip sweat on your back. Opens his left eye at you, iris dilating. “Come on, fuck me!”

Lets out a thunderous laugh as he rams into you faster, harshly pulling up and down on your skin with each movement. “i’m not your matesprit. you’ll take whatever i feel like giving you.” His voice sounds strained. Mewl and push your hips back against him, rubbing your thighs together for as much stimulation as possible. Might as well enjoy what you can. “heh heh, that’s better. good human.” You snarl at his condescending tone, but stop caring as he gets more vocal. Swearing and grunting, he must be close. 

Before long it seems like he’s finishing. Squeezes your ass so hard you shriek for him to let go. He heaves out a zealous sigh, magic cock pulsing, shooting something incredibly hot all over your back. He reclines, sitting back on his knees and admiring his work. Pokes at your privates, then moves to contently pat your butt. “geez, pretty hot under the collar. i’m _ass_ tounded by how much you must’ve liked that. you’re pretty nasty, kid.” 

Eyes return to their white specks, ridiculous porno cock evaporating. The warm fluid on your back disappears too? That’s convenient. Throw the robe to cover you again, rolling over and pulling the blankets over you. “Get out so I can fucking masturbate.” Lean against the pillows and immediately reach down to touch yourself.

He chuckles and stands, buttoning his pants. “looks like i don’t need to get to the _bottom_ of what you’re doing with your night.” Twist up your face but don’t respond to him. Busy. He reaches down and picks up the book he threw, inspecting that he bent the cover. “ah man. isn’t this papyrus’ book? whoops.” Has a forlorn expression as he sets the book on your table. Shoves his hands in his pockets and he’s out the door. Doesn’t even bother to close it behind him. Ugh, finally, byyye. Grab a couple things from your sex drawer.

“oh, by the way,” his head pops in and you scream lightly in surprise. “i’m fucking your asshole tomorrow night. so make sure you’re prepared,” he winks, “have fun. don’t get too pooped.”

… Think on that for a moment. Yeah. Alright. I’ll let him fuck my ass. Lay down a towel, put on some rubber gloves, lube up your solid, steel butt plug and get to work.


	6. Chapter 6

**Summary for the Chapter:**

> Buttstuff.

**Notes for the Chapter:**

> I really really loved writing this chapter (¬‿¬) I hope you guys like it too. Readers gender and genitalia are left to interpretation, although them having a vagina is slightly implied.

Alright. You’ve done the necessary preparations. Pooped ahead of time. Put towels all over your bed. Gotten yourself nice aroused and kept it that way all evening. You’re not going to go the whole nine yards and giving yourself an enema, that takes for fucking ever. His magic dick might get a bit brown, but he’ll just have to deal with it. Getting dirty and having an authentic sexual experience is part of fucking a human.

Watching TV with Papyrus. He’s knitting some new socks. You’re hiding under a blanket, discreetly touching yourself. He might notice, but you don’t think he’d even care if he knew. Just chalk it up to human weirdness. Papyrus is a surprisingly accepting monster.

Sans appears out of nowhere like fucking always and scoops you up in his arms like you’re a couple on your honeymoon. You complain, “SANS,” almost stabbing your genitals as you’re jostled around. “FUCKING. A little WARNING next time?!” He just winks, his open eye sparkling. He looks way too happy right now.

Starts walking towards your room when Papyrus turns around on the couch to yell at the two of you, “SANS!” The blue coat wearing skeleton stops immediately and looks at his brother, paying your half-hearted struggling no mind.

“yeah, bro?” He looks a little nervous. Maybe he wasn’t expecting his brother to intervene.

Papyrus has a little pink blush on his cheeks, aaaahh, that’s adorable. “YOU’LL MAKE SURE THE HUMAN IS… UNHARMED, RIGHT?” Oooh Papyrus~! <3 He cares about you so much. Makes your heart flutter. Wait, unharmed? Oh shit. How much does Pap know?

Sans gives you a loaded look, then smiles cheerily to his brother. “don’t worry. they’re safe with me.” That’s fucking rich. “we’ll be back soon.” Doesn’t even try to explain himself, he just continues on his way to your room. Can hear Papyrus sigh in the background. Feel guilty. You hate leaving Pap in the dark about anything. Especially something so close to home. Falling in hatelove with his brother.

In your room, he sets you down surprisingly gently and locks the door. Drop the cocoon blanket and reveal your sexy lingerie. Garter belt holding up your thigh high socks, open cup bra, and that’s it. No panties. Sans just looks as you for a few moments as you stand there. You snort and spin to show him how nice your ass looks. “What’s wrong, Mr. The Skeleton?” Lean into him and press your butt into his crotch, “is the human getting to you?”

Up against the wall, one hand held behind your back, face pressed against one of your posters. You laugh, accepting his immediate confrontation as a victory. Teeth sink into the skin between your shoulder and neck, clenching fucking mercilessly. Struggle to hold in your exclamation of pain. You don’t want Papyrus to interrupt you or worry. A skelehand reaches between your legs and frantically gropes at your swollen nether regions. “you smell so good,” his voice is husky. “been touching yourself all day, haven’t you? such a naughty little slut.”

Moan lightly and spread yourself to his touch. So close already. You fucking need release. “Yeah yeah, I’m a dirty whore. I’ve been teasing myself all day, just touch me and make me cum so we can fuck.” He chuckles against your shoulder, hand gliding effortlessly to that sensitive spot and rubbing hard. Dammit, he feels so good, he’s so rough and smooth and warm and— you cum unexpectedly, the less than satisfying orgasm rushing through you. You grumble with frustration, wanting that to have lasted longer. Pant against the wall, blushing deeply.

“that was easy.” He fucking laughs at you and rubs off his juicy fingers on your thigh. “are all humans this desperate?” Whirl around to face him, adjusting your sensitive genitals as he pulls his cock out of his shorts.

Ugh, it’s still the same ugly porn penis. Scamper past him to your end table, pulling out your favorite dildo. “Can you turn your dick into this?” He follows you, snatches the toy, and gives you a shit-eating grin. “What,” you say flatly as he stares.

Holds it up to the light, inspecting the dildo like it’s a fucking diamond or something. “geez kid. bit of a size queen, aren’t ya?” You’re flattered and pissed off at the same time, asking him not to use gendered nouns like that. He quickly apologizes. Clears his throat, beads of sweat collecting on his brow. Look down at the dripping flames smoldering between his legs, the magic forming into something new: your favorite dildo!

Hell yeeaaah. “I’m in charge tonight,” you declare, grabbing him by the collar and trying to push him onto the bed. He’s so fucking dense you can’t even move him an inch. He just chortles. “On your back on the bed, okay?” 

Doesn’t move, “why should i listen to you when i can just take what i want?” He reaches to grab at you and you hop away, slapping at his hands.

“Look, I don’t know how monster assholes work, but human assholes are super delicate. I’m in charge so you don’t rip me in half.” 

He seems to get the picture, starts taking off his jacket and lazily flopping on the bed. Tucks his hands behind his head, blue appendage sticking up invitingly. “alright,” he says casually, “then come sit on my lap.”

Okay… you can do this. Take your time crawling on top of him, sitting on your knees, legs around his pelvic bone. Apprehensive. You’re about to have sex with Sans, this is a pretty big deal. Snatch up one of the various types of lube from your table, squirting a generous amount on your palm. Too much lube is the right amount of lube for anal. Rub it between your hands. Start jacking him off, coating his dick with lube at a leisurely pace. Reach down and play with your rectum, circling, inserting one finger just an inch.

Sans grunts, scowling and lightly thrusting up into your hand. Must be getting impatient. Gasp, two fingers now inside you. He’s kicking his foot. Looks like he wants to say something. He doesn’t.

Remove your fingers and grasp him tightly at the base, aiming him to your opening. It’s warm and tingling against you. Okay… Breathe deeply. Caress your already swollen genitals as you lower yourself onto him. Very slowly. He holds his breath, then lets out a sigh as you stop. An inch inside. You whimper, your body stretching to accommodate the new obstruction. It hurts. Burns. He notices your tension and extends his arms to cup your breasts. “hey,” he says softly, “you okay? relax…”

Nod. This situation is so intimate and red-leaning, you have to look away. That glowing eye looking at you with genuine sympathy is way too intense. And not what you’re used to. His thumbs find your nipples, flicking at them delicately. Lower your hips. Take your time. Play with yourself. Until he’s finally fully inside and you’re sitting on his femurs.

“s-shit, kid,” he stutters, “it’s really tight.” His faltering voice boosts your ego, giving you enough confidence to grind your hips into him, his cock pulling at the tissue inside you. Moan as the tip finds that bunch of nerves. He grins like a dope, hands moving from your chest to your love handles. “so smooth… mmmnn, does it hurt?”

Lift yourself an inch and buck back down. “A little,” you whine, “but I like it.” His smile turns predatory as he digs his fingers into your flesh. “You can start moving…”

“i don’t wanna be a _pain in the ass,_ but,” immediately, he starts thrusting, cutting off your groan of annoyance. Holds you in place on top of him as he pumps in and out of you with the entirety of his length. “ooh, fuck yeah,” his voice is low and throaty, god, that’s hot. “that’s good, that feels really good. that’s right, play with yourself, let me see.” Spread your legs and present your arousal, the large insertion in your ass causing your genitals to bulge out with each thrust. His guttural moan confirms his approval. “hey,” he pants, his sweat accumulating on your pillows, “wanna hear a joke?”

You growl and rut your hips into him roughly, “no, I really don’t.”

Still pumping into you. Starts chuckling prematurely, “what’s it called when someone butt dials you?”

“Sans, shut up. Just fuck me.”

“a _booty call._ ” He continues to giggle at his own stupid joke. “sorry. that’s all i’ve got, i think i’m at the _rear end_ of these butt puns.” Stops moving as he looks into the distance, apparently trying to think of another joke.

A furious scream erupts from you lungs as you lean forward, grasping his clavicle and pushing down, “I HATE YOU!” You hear a loud **crack.** Was. Was that a bone? Did you just hurt him?

His sockets are empty. Black, hollow. There’s darkness and static in your head. When you’re able to comprehend reality again, you’ve switched positions. Missionary, he’s between your legs, still inside you, towering above you. His dick swells, stretching you out even more, making you cry out in pain. It burns, fuck, it hurts, it burns!

“Ahh!!” tears are welling in your eyes, hands helplessly pushing at his hips. “It’s too big! I-I can’t…!”

Cyan eye burning again, he pulls out and pushes back in, satisfied with the disjointed moan that bursts out of you. Wraps his phalanges around your throat, gripping tight enough to remind you that he could kill you if he wanted to. “do you want me to stop?”

“No! Nonono, don’t stop, just, oh god oooh god, FUCK!”

Completely exits your body. Reapplies some lubrication. Buries himself to the hilt. Tears start flowing. He’s laughing. “i hate humans. **all humans.** good for nothing, murderous, sex-crazed **monsters."**

You whimper, the words stinging almost as much as his cock. He’s so big you can feel him pushing on your bladder. In the smallest of whispers, you repeat, “I hate you.”

Roaring with laughter, he’s moving fast, oh god, you think you’re about to climax. “i hate you too, you fucking useless human.” Squeezes your neck. Grabs your calf with his other hand, tossing your leg over his shoulder so he can plunge even deeper. “ah yeah,” he’s thrusting frantically now, panting heavily. “fuck, fuck!” Scorching liquid shoots deep inside you, eye bursting with magic, hand on your throat tightening so hard your vision blurs. Motionless for a moment. He sighs, smirking happily at your weeping, flushed expression. “you look pretty good right now, kid.” Static, then you’re empty and his eyes are back to normal. 

You whine and buck your hips up at him, hands lovingly stroking the bones of his arm. “heh heh. want some help? alright. i’ll throw you a bone.” He sits cross legged, releasing your neck, and dancing his fingers across your privates. He’s patient, watching your reactions to see what works best. Brings you to orgasm and you crumple under his touch. It feels so good and the experience you just had was so intense, you start crying. 

He rubs his hands dry on the towels lining your bed and scoots to the edge to stand. Puts on his jacket, pulls up his shorts. Turns over and strokes some of the hair out of your face. He gapes at you awkwardly while you sniffle and wipe the tears away with your forearm. “uhh.” He’s blushing. Throws up his hood and hides in it. Hands shoving into his pockets. “i’ll see you later.” Shuffles out the door. Doesn’t close it behind him.

Lie there and sob for a few minutes. Reach down to inspect the damage. A bit loose. It’ll be okay. Remove the lingerie and wear your robe to the bathroom where you shower. Ask Papyrus if you can sleep with him in his bed tonight. You need some cuddles. He says only if you read him a bedtime story. Break down crying in the middle of reading. Recover quickly, apologizing. He asks if something happened. You tell him yes, but you’re happy about it. He doesn’t push any further. Says you can share his bed any time you need to. His sincerity and kindness brings you to tears.


	7. Chapter 7

**Summary for the Chapter:**

> Breakfast and feels.

**Notes for the Chapter:**

> I wrote this on a plane, the woman next to me kept reading it haha. I hope she enjoyed it. I hope you guys like it too. Readers gender is left to interpretation and they have a vagina.

Things have been. Really. Well. What brief exchanges you have had with Sans have been awkward. He’s avoiding you again. Goes to work, eats at Grillby’s, and when he’s home he’s in his room. You ask Papyrus if Sans has said anything. He says no. Says Sans acts normally around him, albeit more quiet than usual. Less puns, more dull silence. He’s concerned.

It’s been an entire week. You went to work each day. Now it’s your weekend off again. Still nothing from Sans other than a few jokes and void smiles. Hurts your feelings. You share your body and true feelings with him and he then hides? Okay, this is bullshit. If he is really in a kismesitude with you, as he has stated many times, he at least owes you an explanation. Corner him some how. Make your point clear. 

First day off. You make breakfast with Papyrus. Blueberry pancakes. Hash browns. Water sausage. Sans didn’t come down. Set up a tray for him. He’ll probably open his door for food. Pap gives you a good luck kiss and says he’ll do the dishes. Thank him.

Up the creaky stairs, down the hall to the last door on the left. Hold the full tray of food like a waitress and knock. “Sans?” No answer. “I brought you breakfast. It’s uh, pancakes, hash browns with ketchup-“ The door creaks open, a very deep socket poking out, flecks of white on the tray. Sans looks at you. “Could… could I come in?” You expect him to snatch the food and close the door. But he doesn’t. Opens the door and steps aside, inviting you in.

Wow, his room is uh. It’s not very aesthetically pleasing. The smell of dirty laundry, mothballs, and old books surrounds you. Clothing and papers everywhere. Bed, a mass of sheets. A treadmill. There’s. A fucking magical tornado in the corner?? With notes and socks swirling in it? What the fuck. This wasn’t what you were expecting. The mess was less terrible than what you imagined, but a lot more bizarre. 

Sans drags his feet as he makes his way to the bed, kicking junk out of the way as he goes. Grabs the wad of bedsheets and pushes it against the wall, crawling onto his bed and using the linens as a back rest. You wearily follow, sitting on the edge of the bed. Springs croak. Place the tray in front of him and he goes to town. Hash browns disappear swiftly. You study him as he eats. Doesn’t look that great. Like he hasn’t slept well in a while. Usual shorts and white t-shirt, some grease stains on it. No jacket. He notices you and you blush, embarrassed for staring.

“So,” you start, “we haven’t really talked since you uh. Fucked up my butt.” Try to laugh, it doesn’t sound natural. 

He doesn’t seem to mind, just continues eating. Chugs the orange juice. 

Fold your hands in your lap. “Any particular reason why you’re avoiding me?”

“yeah,” he mumbles, mouth full of blueberries. “a couple reasons.”

Okay, this is good. He’s talking to you. But he doesn’t continue. Don’t push too hard. “Well?” you ask, “can you tell me?”

Finishes his meal, sits back and pats his ‘full’ belly. You stopped questioning how a skeleton gets full or even having a stomach filling his shirt at all. “i mean, i could tell you,” his Sansy grin comes back and he winks at you, “but it’s kinda more fun this way.”

“ _Fun?_ ” you spit out, “you look like shit, Sans. You aren’t having fun and neither am I.” You’re angry.

He unceremoniously drops the tray on the ground, empty cup tipping over, silverware clinking. Reaches over to you and cups your face in his skelehands. He’s cold. The sudden tender physical contact causes repressed feelings to resurface, eyes starting to water. He looks hurt.

“Y-you.. you used me. Then you left.” Droplets streaming down your face. He wipes them away with his thumb. Try to turn away, can’t, kept in place by his palms.

He sighs and looks away, “i’m sorry.”

Sniffle, bottom lip quivering. “Why…? Why did you?”

Still. Silent. After a few moments of you regaining your composure, he leans in and. Kisses you? That’s what you interpret his teeth pressing against your mouth as. Pucker your lips up against him and he hums happily. You’ve never kissed him before. It feels so concupiscent and amorous, you don’t know how to respond other than to reciprocate. Static in your ear. A tingling appendage runs across your mouth. Open and accept it inside you. No taste to it. Twines with your tongue. Hands snaking up the front of his shirt. He pulls back and rests his forehead against yours. He’s starting to perspire. Cheek bones blushing. Blue smoke smoldering around his left eye.

“do you really hate me?” he asks.

The question surprises you. Fingers curl around his bottom rib and he shudders. Pull him closer to you so he’s almost sitting in your lap. “… In the way that someone hates their kismesis. Yes. I do.” He lets out a fluttering chuckle and leans into your touch. Creep up each bone, counting them. 24.

Hands drop from your face and circle around your torso, running down the center of your spine. His voice unchanged, he says, “what do you hate most about me?” Pulls up your shirt and reaches into the seat of your pants. Moan quietly, looking away as he nuzzles into the crook of your neck.

The same magical tentacle that was in your mouth finds your collar bone and traces it. Whimper as he possessively clutches your ass cheeks, lifting and spreading them. “Your puns.” He sneers and reaches lower, finding the heat growing between your legs. “They _were_ okay, but… mmmph,” pause as he pokes at your entrance, “you make them all the time… and at, aah, the worst moments.”

Feels that you aren’t that damp yet and pulls back, moving to press his body flush against yours. His bones feel nice. Hands still cupped against your tush, he effortlessly lifts you and sets your back against the wall. You’re now on his lap, legs spread, he’s on his knees beneath you. One hand fondles your breast over your top while the other clumsily starts removing your pants. He eventually gets them off.

“You’re such an asshole sometimes.” Tense up when his phalanges find the crotch of your panties, relax as he takes his time exploring. “Not to mention sadistic.” Sans laughs at that and confirms your point by striking your inner thigh with his fist. “You— ahh!” you’re cut off as he punches you again, digging his knuckles into your muscle. You enjoy the pain and can feel that energy traveling right to your genitals. “Ugh, you’re so haughty about some things, you **need** someone to put you in your place once in a while.”

“put me in my place, huh?” He scoots up and grinds the bulge in his shorts against your underwear.

“Yes,” you huff, “that’s what I just said.” Pull his shirt off in one quick motion. It’s about time he started getting undressed along with you. He flushes even deeper as your eyes roam his unique body. Note the dull glow behind his ribs. Remembering how this all started, “you stringed me along for months… Toying with me.” The skeleton gasps as you shove your hand into the energy centralized in his ribcage. “What kind of person does that?”

He seems paralyzed as you fiddle with the heat that you can only assume is his soul. Start rubbing yourself with your other hand, rutting your ass down against his concealed member. “You called me useless.” Pull your hand back slightly from his warmth.

He chokes out a heavy breath and shrugs, “m-most humans are.”

Clench your fist into the heat, making him freeze up again. “I’m not most humans.” Remove your hand completely.

Pulls your shirt up to expose your chest. A low rumble bellows from his throat as he leans down and encircles one of your breasts with his tongue, teeth finding the hardened tip. You squeal and wrap one arm around his neck, holding him close against you. Continuing to play with yourself, he joins you, teasing out wetness as your clit swells under your fingertips.

Translucent dick bouncing out, waistband resting where his femurs meet his pelvic bone. His tongue and teeth still roam the skin of your chest, leaving several bites marks in his wake. Move your hand from your heat and grasp his pubis, using it like a handle to rub his magic against you.

“Aaahnn…” His member pushes between your folds, bunching up the moist fabric of your panties. “You don’t hate me, do you?”

Sans doesn’t say anything. Hides between your breasts. Your panties are gone. The tip teases your entrance. You can’t believe how badly you want him. Tug him into you by his pubis in one smooth motion. You moan together. “fuuuuck,” he breathes as he pulls out and looks down where the two of you connect before going back in. “this hole’s even better.” You snort, amused by his words. “geez you’re.. you’re pulling me in, holy shit. it’s so… hnnnng..” He trails off as he starts a steady rhythm.

Your hands move to run across his upper body, he feels warm again. A thought comes, “are you in love with me?”

Stop thrusting. Oh shit. Is he actually in love with you? He plunges into you suddenly, ramming against the tender erogenous zone inside. You groan and lean on the wall behind you, throwing your head back. “Oh my god,” you pant, “you are!”

“no.” He’s still looking down. Rests his hands on the bed to support his weight as he thrusts. “i’m not.”

“Aww, ah, that doesn’t sound very convincing.”

“i don’t know, okay?!” his voice is uneven. He’s shaking. Your heart stops. He’s finally being honest. Still avoids making eye contact, wraps his arms around your waist, hugging you to him tightly. His ribs dig into yours. “i… i don’t know.” His hips slow again. Wrap your legs around his spine. Don’t move yet. Wait.

“i hated you. or i thought i did. but after i fucked you…” his train of thought pauses, but his shaft once again starts moving, pounding so hard into you, steadily, his pelvis bruising your buttocks. “ahh.. you looked so happy. you were so.. vulnerable. and to think i made you like that… and that you not only let me, but you liked it.”

“Sans!” Finally, he looks up to see your face, blushing and teary. “Keep going… I’m getting close.”

He’s smiling. Reaches between the two of you and rubs your hardened sexual organ.

You’re about to cum but you don’t want to make a mess of his already trashed room, “w-wait, I’m gonna squirt!” That seems to only egg him on more, picking up the pace to a speed that no human could ever match. 

“sometimes you just gotta _go with the flow,_ ” he snickers.

There’s no way you could have held back the scream that bursts from you, muscles clenching around him so tight that he’s forced out of you, fluid soon following, gushing all over his lap and the bed beneath him.

“wow,” he whispers, “you got me _soaked to the bone_ here, kid.”

You catch your breath and reach down to stroke the sensitive organs between your legs, “ahh, you can continue if you want.”

Reenters you immediately and bucks like crazy, “you don’t have to tell me twice.” You’re sore, but it’s pleasant. Watch him, he’s sweating, the glow behind his ribs fluctuating. He fucks you into the mattress until he finally finishes, jets of magic jizz coating your cervix, his eye and soul blazing wildly. 

He stays inside you for a few moments. The connection between you severs, magic fading away. Scoots away from the wetness absorbing into his bed and reclines, closing his eyes. “Sans?” He. He starts snoring. How did he fall asleep so fast?

Redress, clean up the mess you made as well as you can. Take the breakfast tray downstairs. Put some clean sheets down. Sans hasn’t moved an inch. Smile as you tuck some blankets around him. You’d sleep next to him if his room didn’t smell so bad. Papyrus says he could hear your scream through his headphones. Apologize, blushing and laughing. He asks if you and his brother talked. You say kinda.


	8. Chapter 8

**Notes for the Chapter:**

> Enjoy, enjoy! The readers gender is left to interpretation and they have a vagina.

You spent the night being spooned by Papyrus and discussing the conflicted feelings you have for his brother. And Sans’ dithering affection for you. Being very careful to leave out the details about the sex and black relationship. Don’t want to divulge too much. Or cause Pap to worry. Most people don’t understand the nuances of kismesitude.

Papyrus tells you Sans lies a lot. He keeps a lot to himself. He pretends like everything is okay when it really isn’t. You mention that his humor is a defense mechanism, Papyrus agrees. He says he understands your uncertainty. But he urges you to keep trying. He says Sans doesn’t do a lot. His older brother hasn’t put effort into a lot of things in a long time. Nothing seemed to help. That’s slowly been changing, ever since you two started messing around. Papyrus thanks you and hopes you continue to pursue a relationship with Sans. You smile and feel warm inside.

The quadrant vacillating is troubling. You want to keep it black. But. There are red feelings that can’t be ignored. Your train of thought is interrupted when you hear your door creak open. Speak of the devil. Sans trots in with a pillow in his arms. 

“SANS!” Papyrus beams, a little too close to your ear. Ow. “WOULD YOU LIKE TO JOIN US? WE WERE JUST… WHAT DID YOU CALL IT, (your name)?”

“Glubbing about feelings,” you respond. Sans grins a bit, probably catching the Homestuck reference.

The skeleton standing at the foot of your bed looks to you for permission. You nod. He puts his pillow next to his brothers head and plops down, bouncing everyone around a bit as the springs of the mattress whine. He sighs heavily, magic smoke visibly leaving his body. Papyrus rolls onto his back and loops his arms around each of your shoulders, hugging both of you to his ribcage. He doesn’t notice your discomfort and you giggle as you pull away, resting your head on a pillow. He starts going on about his relationship with Undyne. Shares the new dynamics that surfaced from her blossoming relationship with Alphys. Before long, the gentle snoring of Sans fills the room. You both laugh. Papyrus continues. His words turn into white noise as you drift off, joining Sans in the realm of slumber.

When you open your eyes, Sans next to you, on his stomach, one arm coiled around your waist. Papyrus isn’t there. Gotta pee. Try to roll over, Sans’ arm doesn’t bulge. Fuck. Struggle a bit. He grumbles in his sleep and hugs you tighter. “Ack!” you choke out, “hey, Sans!” Yell and start shaking him. No change. Extend your tongue and shove it into the small hole where his ear would be.

“GAAH!!!” Sans screams and leaps off the bed, left eye suddenly gleaming. A… a large canine skull appears above him, white eyes staring, jaw unhinging. Just as quickly as it manifested, it poofs away in a cloud of blue smoke. You’re just sitting there on the bed, surprised you didn’t piss yourself. “geez… kiddo, don’t scare me like that,” his hoarse voice manages to get out. Sans struggles to catch his breath, holding the wall behind him for support. Eyes back to normal, sweating.

Gape at him, a dazed grin stretching across your face. Raise a trembling finger to point at the space were the floating head was, “that could’ve killed me, right?”

He mumbles and uses his shirt to wipe off some perspiration, “yeah.” Takes a few minutes to calm down before he returns to his lounging position on the bed.

Adrenaline and heavy emotions are swimming inside you. You give him a shit-eating grin and say, “that’s kinda hot.”

“… _what?_ ” he replies.

The urge to urinate surpasses everything else and you sprint for the toilet. Relieve yourself, wash your face, brush your teeth, return to a still jumpy skeleton. Don’t bother to change out of your nightwear. Sit next to him, wicked smirk returning. “You could kill me so easily. Without even trying to. That’s, haha, that’s kinda hot! I’m into it!”

Sans gets that predacious looks that he gets whenever you do/say something especially titillating. “oh yeah?” he growls as he sits up and pulls you to him, rolling you over until he’s on top of you. On his stomach, half of his body covering you. Femur pressed between your legs. He’s heavy. Phalanges lazily pinning your arms above your head. “does the human want to get messed up by the big, scary monster?” Uses the elbow of the arm pining you down to prop himself up, wanting to observe your reactions.

Shit, this is hot. Already feeling pretty turned on. Hum gaily and arch your back into him. His otherworldly body feels so good against you, no flesh to cushion the impact of his touches, no buffer to protect your soft tissue. “Mmm, oh yes, you ravenous beast. Fuck me uuup~” 

Clamp your thighs around his bone and get what stimulation you can from rubbing against it. He chuckles at you, “so needy already.” Free hand grabs a fistful of your shirt and literally rips it off. The force of the fabric tearing around the curves of your torso burns at your skin. You like it. Using the tattered remains of your top, he haphazardly binds your wrists together above your head to the posts of your headboard, murmuring, “you actually like the idea that i’m dangerous…” On his knees, crouched over you. Reminds you of that first night. When you confessed your feelings. “you’re really kind of a freak, aren’t ya?” Without warning, his fist is colliding with your sternum, a strangled breath shotgunning out of you lungs. He holds it there, knuckles jabbing firmly.

His cyan eye, that almost evokes a pavlovian response in you, alights, magic crackling. In a hushed voice, he says, “i’ve killed you before, you know.”

The skelehands that clench unforgivingly around your breasts can’t distract you from what you just heard. He’s kill you before?

Almost don’t hear the door whisk open, but you sure do hear Papyrus’ anguished voice. “OH, COME ON YOU TWO!!!” Sans hops off and takes a seat next to you, blushing madly. He grabs the pillow from behind your head, much to your chagrin, and uses it to cover your bare chest. The tall skeleton, wearing a laced apron and holding a large breakfast tray, matches his brothers blushing face as he rants. “YOU NEED TO STOP CANOODLING AND START TALKING ABOUT YOUR FEELINGS!” 

You and Sans look at each other with blank expressions, remain silent, then turn back to Pap. He sets the platter down on your dresser and throws his arms up in exasperation. “THE SAME THING IS GOING TO KEEP HAPPENING UNLESS YOU TALK. ABOUT. IT!” He huffs and puffs for a while before actually taking a good look at the precarious position you’re in. “WOWIE,” he says flatly. Quickly turns on his heel, probably so the two of you can’t see his flustered visage, and heads out the door, declaring, “ENJOY YOUR BREAKFAST, BROTHER AND HUMAN.” Door slams shut.

You two sinners just sit there for a minute and then burst out in laughter. Tears are welling in Sans’ sockets as he collapses next to you. Both of you still cackling, your monster lover/hater lies on his side next to you, spreading your legs by trapping your thigh between his femurs. “i can’t believe my baby brother caught us, holy shit.” Rests his cheekbone on his fist and fiddles with your underwear, finding it surprisingly moist. “man, that shouldn’t have turned me on. guess i’m not one to kink shame, huh?”

Moan and arch into his touch, spreading yourself wider, inviting him to do whatever he pleases. “You actually LIKE getting caught?” Pull at your restraints as his hand dives into the front of your panties, coating his phalanges before shoving three of them inside. “Ahh! Ah, oh, that’s tight.” Stare at the tray of food and feel the guilt start to set in, “oh man, poor Papyrus.”

Sans snorts as his fingers pump in and out of you, white lights in his sockets being replaced by that single, glowing iris again. “he’ll be fine. probably gonna jack off to the sounds you make, though.” The carnal grin he gives you as he fingers you harder would probably disturb you if you weren’t also a kinky weirdo.

“Oh yesyes, keep fucking doing that,” you squeal out as he stabs into that spongey tissue, hitting it so hard a few teaspoons of cum leak out of you. It’s probably getting bruised at this rate and that feels fucking awesome. Another finger inside, he’s so tantalizingly close to slipping in that whole fist. Neck hurts from craning up to look at him, you ask him for your pillow back. He grabs you by the hair and holds you up by it, shoving the pillow behind your head. Let’s you go and removes his phalanges. Still lying on his side, he rotates you to face him, twisting the shirt around your wrists, tightening it. Hands starting to go numb. Sans asks if you can feel any tingling in them. You say no. Tingling with bound arms is a sign of a possible nerve damage, so watch out for that.

Panties are roughly split open at the crotch. Gym shorts, still stained from yesterdays orgasm, pulled down. Rests his head on the pillow next to yours, hoisting your leg up and over his hips. Looks to you for permission. You give it. He’s staring at you as he slowly enters, the intensity too much. Close your eyes. He once against compliments how snug you are and how good you feel around him. Too red too red, go back to black please. Say something to break the lovey-dovey atmosphere, “mmmph, Pap’s right, you know.”

Fully inside. Cups your ass to push you away and then pull you back onto him. Sans doesn’t say anything.

“Our quadrants keep vacillating.. Nnng, we need to talk about it and come up with like… I dunno, a schedule or something.” Move your hips against him, doing a majority of the work. 

Chuckles at your comment, “what, are you karkat now?” He contently watches your body jiggle and flex as you do your best to ride him.

An idea comes. “Or maybe I could just keep fucking with you to keep you caliginous.” He seems to like that. Begins to plunge into you, holding your hips still. Finally look him in the eyes and smirk nefariously, so many possibilities flooding your mind. “What if I fucked your brother?” you sneer. He gets quiet. “He’d probably be up for it. How would that make you fee-OH!”

He thrusts into you so hard. Uses his cock to force you on your back. Missionary position. Looming over you. He looks. Jealous? “fuck that,” he barks, his magic swelling, filling you at an uncomfortable rate. “you’re _mine,_ do you hear me?”

You whimper loudly from the extended cock inside you, repositioning your legs to try to get as comfortable as possible. “No I’m NOT!” The same skelehand was recently inside you collides with your face, wetness smeared across your cheek. Did he just SLAP you? Okay, you’re livid. “You don’t own me, you don’t own SHIT, you sham, you fucking **COWARD!!** ” Wad up the accumulated saliva in your mouth and hurl it at him, hitting so hard it makes an audible _splat._

Sockets in his skull are empty again. Spit trailing down his face. The fear that flutters in your stomach travels right to your groin, muscles drawing him further inside you. Lick your lips as his grin slowly broadens. Smile back at him, eyes wide, probably looking like a lunatic. “Do you hate me?”

No response.

“ _Show me,_ ” you taunt.

Left eye flickers back. Both hands wrap around you neck. Squeezing tight, pressing on your blood vessels and windpipe. It hurts. You can’t breathe. He pulls out, yanking on your tender muscles as he does. Releases your throat, directing you to look between his legs where something new is forming. Blue fumes smolder and hiss. When they dissipate, Sans has two cocks sticking out from his pubis. Bottom one a bit smaller. Breath hitches in your throat. He’s going to DP you. You’ve never done that with anything other than toys. They’re big. This is going to hurt.

He reaches down and aims the tips to each of your orifices. Pushes his hips forward and you scream, “BLUE STOP SIGN!” The safeword you two had agreed upon in the very beginning, before he even snuck up on you at work. This was the first time you had to use it. 

Sans stops and pulls back immediately. Expression changing from grisly to worried. “what’s wrong? is it your arms? did i choke you too hard?”

You roll your eyes as dramatically as you possibly can and extend your leg to kick the end table. “My ass needs LUBE, dummy.”

“oh,” he says simply, then reaches into your top drawer for a bottle. “i knew that,” he comments as he squirts some directly onto the magic protuberances between his legs. “i wasn’t gonna fuck you raw, i just wanted to get _under your skin._ ” He winks, moaning quietly as he thoroughly lubricates himself. “no lube, that would be pretty grave, huh. but i can _dig it._ ”

Growl out of frustration and kick at him, quickly stilling the moment you feel him return to your openings. Looks you in the eye, thumbing at your clit, smiling conceitedly. “say it,” he demands, “say you hate me.”

TO BE CONTINUED

**Notes for the Chapter:**

> This was getting super long so I decided to split it into two chapters. You'll get the next one in a while ;) thanks for reading!
> 
> I got the 'blue stop sign' safeword idea from this fic http://crawlingsins.tumblr.com/post/132838587391/the-other-side-part-3-sansreader which is totally awesome and I recommend it.


	9. Chapter 9

**Summary for the Chapter:**

> Make sure you read the previous chapter first! Double penetration time ᕕ(ᐛ)ᕗ Enjoy!

**Notes for the Chapter:**

> The readers gender is left to interpretation and they have a vagina.

“say it,” Sans demands, “say you hate me.”

Upper lip curls disdainfully and you say, “I hate you,” as monotonously as you can. “Listen to me.”

Sans’ sockets widen and he perks up, giving you his full attention. 

Deep breath. Arms still bound above you, chest heaving up and down from excitement, nipples hardened from the chilled air of your room. The feeling of two, hot magic-shafts tingling against your body is fucking distracting. “Look, I’ve never been double penetrated like this before.” 

Rotating his hips slooowly to circle your holes with his dicks. “a DP virgin, huh? you’re not telling me a _fib_ ula? shit, kid, i’m so surprised i could do a _double-take!_ ” he says theatrically as he looks away then turns back quickly, making a ridiculously shocked expression.

Clench your teeth in vexation, feeling a vein on your forehead pulse. “So. Just take it slow. Oh, and untie me.” He makes a pouty face and mentions how good you look _all tied up,_ then yanks your hands free. Grumble and pull your arms to your sides, make a fist and release, blood coursing through your fingers. Grab a pillow and shove it under your butt, elevating yourself to him. Recline. Curl your legs around his pelvis. Blue tips kiss your orifices again. Force him into you by hugging your calves closer. He glides in rather easily. But it’s so intense. Probably the most intense penetration you’ve ever experienced. It’s snug. Tissue burns. Release a tortured cry. Halfway inside. So **tight!**

Been focusing on the sensation between your legs, you don’t notice him until he exhales so heavily it whistles between his teeth. Bones quaking almost audibly. Phalanges on your thighs quivering. “… (your name),” Sans chokes out. Haven’t heard him say your name in so long. “you look… pretty good right now.”

Give him a weak smile, trying to act like he isn’t affecting you as much as he is. Pull him closer. Another inch or two. Fully inside. Fisting the bedsheets. Toss your head back into a pillow and moooaaaan, “oh my GODDD!” Rotate your hips to feel him rubbing together inside you, pinching your perineum.

“heh heh,” he chortles, “think you can trap me in your vice grip, human?” Waits for you to give permission before pulling out at a leisurely pace, then reentering. “ahh, well… it’s working. you’ve got this monster _on his knees._ ” His voice is so strained, he’s perspiring, still quivering as he reaches to press down on your lower stomach. Thrust. The hand below your navel squeezes your g-spot against his shaft, wresting more cum from your urethra as he thrusts.

Heave out another pleasure-induced sob, “oh my **GOD!!** ” It’s so overwhelming, you can barely register what he’s saying. Probably couldn’t orgasm from this, at least not the first time. Your body is too busy adjusting and processing to even contemplate completion. “HolyshitholyshitholyshitFUCK,” you curse as rhythmic plunging commences. It hurts and it’s a crazy amount of overstimulation, but you love it. “FUCKYESkeepgoing!”

Unrestrained aquamarine flickering all around his skull and glowing behind his t-shirt. Cheshire cat grin as he ogles at you. “fuck yea, (your name). you like that? you like getting filled to the brim by a dangerous monster?”

“YES!” you bawl. Stabbing into your body as deeply as he can, steady pace, but you can tell he’s holding back. Drool starting to trickle. Hair matted to your face from the sweat and tears. “Hitmehitme, please!”

He grants your wish, fist cannoning into your gut before your eyes can register it. Wind knocked out of you. Struggle to breathe, lungs expand with one large intake of air, forced back out again as he slugs you in the sternum, pain exponentially worse than the first time he hit you. Repeat, “thankyouthankyouthankyou,” as he continues to just fucking ravage you.

As you’re asking for another beating, trembling skelehands cup your face, and he’s leaning down to ‘kiss’ you. “s-say my name,” he’s so warm, he’s so close you can smell his breath.

Beam, hugging your arms around his neck, “Sans!” Sob into him, just letting his teeth brush your lips.

“again.”

“Sans!!”

“aww, louder!”

“ **SANS!!** ”

Before you finish saying it, scalding magic being is released inside. It’s SO hot, it’s WAY too much and you pull away until his dicks pop out, swaying and emptying the last teaspoons onto your thigh. They disappear in a poof along with the jizz, Sans’ sockets, once again, unlit, and he crumples. Belly flops onto the bed. Remains motionless while you reach over his limb, draped over your torso, to stroke the swollen nerve bundle that’s just begging for attention. He pants in your ear whilst you bring yourself to orgasm, squealing as your incredibly sore muscles flex, clit inflates with blood, oxytocin engulfs your brain.

Aftershocks begin to dwindle, aching pain and heavy emotions flooding back. Even though he made no indication of abandoning you, you completely break down, clawing at him. “P-please don’t leave!” you sob, “I-I-I need you. Please don’t leave.” 

He rolls onto his side and guides you to his chest, embracing you. Eyes too watery to see what expression he’s making. “don’t worry, kid,” he says reassuringly, “i’m not going anywhere.” He smells bad. Needs a shower and change of clothes. 

You’re relieved. Take a few deep breaths to calm down. Cuddle him for as long as you can stand, but he just reeks, have to jerk away. “Ugh, you really stink,” wave your hand in front of your face, “how can a skeleton even have body odor?”

Looks at you densely, then chuckles. “who nose? please acseptum my apology.” He’s turning to lie on his back and you know what that means.

“NO no,” you bark, using your legs to try to push him off the bed. “You’re gonna fall asleep and fill up my whole room with your stank.” Strong leg muscles manage to move him a few inches, even in your weakened, post-sex state.

“you’re gonna kick me out, just like that? i thought you _needed me,_ ” he adds with a wink.

Glower at him. He remains stationary.

“tell you what,” he finally says. “i’ll leave if you pick me up and take me to the shower.”

Sit up too fast, blood rushing to your head. Pretend you aren’t that dizzy and reply, “are you kidding me?! You weight like a million pounds!” Pick up his arm and drop it with a thud to prove your point. “AND I just got fucked to oblivion.”

Sans shrugs, “okay, have it your way. i’ll catch you later then.” Shuts his eyes.

You seethe and hop off the bed, giving your legs time to adjust. Walk over to his side and scoop your arms around his shoulders and under his thighs. His sockets are still closed, but he’s wearing a big smile. Squat a little, straighten your back, and lift. You let out dramatic Dragon Ball Z inspired shouts as you engage just about every muscle in your body, hauling his upper body and legs from the mattress. Unfortunately, your human brawn just isn’t enough and you drop him with a strong sigh, releasing him.

He laughs as you rub your lower back, leaning back to crack it. “wow, i wonder if all the weights you destroyed exercising go to heaven. heh heh, i didn’t even expect you to try. i guess you deserve a reward.” Stands to meet you, bones creaking and scraping as he does. Looks you over, you’re still in nothing but a ripped pair of panties, then gives you a solid slap on the ass. You eep and shove at him. “come on, kiddo,” he says as he drags his feet to the door, opening it, and directing you to follow, “you don’t exactly smell like a buttercup either.”

**Notes for the Chapter:**

> These stupid puns are hard to come up with >_>


End file.
